In line with the pre-selection from SDSS, we clearly see an emission line signature in the DLA core at the expected position based on the SDSS spectrum. This is also evident from the reconstructed 2D spectrum from the PCWI datacube (see lower panel of Fig REF ).
To quantifying the detection significance of the Ly\(\alpha \)  emission, we
first need to account for any correlated noise introduced by the resampling of
individual pixels in the final data cube. Such correlated noise typically results
in an underestimate of the effective noise inside an aperture and, thus in an overestimate of the real \(S/N\)  of a source [1]}, [2]}.
